Internal combustion engine

ABSTRACT

An internal combustion engine is provided, on an intake side of which intake manifold pipes are provided and on an exhaust side, exhaust manifold pipes. The intake manifold pipes and the exhaust manifold pipes are connected gas-tight via an acoustically permeable membrane.

This nonprovisional application claims priority under 35 U.S.C. § 119(a) to German Patent Application No. DE 20 2006 010 537, which was filed in Germany on Jul. 8, 2006, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an internal combustion engine with an engine block that has at least one cylinder, on the intake side of which intake manifold pipes are provided and on the exhaust side of which exhaust manifold pipes are provided. The intake manifold pipes branch off from an intake line and the exhaust manifold pipes open into an exhaust collection line. A fuel-air mixture can be supplied over the intake line and the combustion gases can be expelled, especially to a muffler and tailpipe.

2. Description of the Background Art

Internal combustion engines that are used for driving vehicles have one or more combustion chambers, to which fresh gas or in general a fuel-air mixture is supplied, which is introduced to the combustion chambers via an intake line, from which a number of intake pipes corresponding to the number of combustion chambers lead to each of the combustion chambers. On the exhaust side, each combustion chamber is followed by a manifold pipe that opens into an exhaust gas line, which leads to a muffler device. “Fuel” is defined as a fluid that is burned in the combustion chamber in gaseous form or as a type of aerosol and serves to drive the pistons of the internal combustion engine.

At least two problems can be considered for the design of these intake and exhaust devices. On one hand, specifications, for example in the highway or air pollution laws, require an adequate reduction of the noise produced during combustion, so that the environment will not be too heavily burdened by the combustion noises and the noise that arises during exhaust discharge because of the pulsating combustion. On the other hand, it is known that internal combustion engines with different numbers of cylinders produce different sounds and that sometimes customers would like for an engine, for example, with four cylinders to sound as if it were a six- or eight-cylinder engine.

Typically, sound damping is accomplished by a dedicated sound damping unit assigned to the exhaust gas pipe or the exhaust gas line. The adaptation of the engine noise, as this may generally be called, to possible wishes of the customer is performed by suitable length and cross-section dimensioning of the exhaust pipe into which the exhaust manifolds open.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an additional possibility for influencing the engine noise.

This object is accomplished in that the intake and exhaust lines are coupled together in an acoustically permeable and gas-tight manner.

Thus in accordance with an embodiment of the invention, the intake pipe is coupled with the exhaust pipe in an acoustic and gas-tight manner, wherein only an acoustic exchange, but not a gas exchange is to take place. In other words, the intake noises supplement the tailpipe noises present in the exhaust line and/or influence them by interference, or vice versa.

The two pipelines are coupled together with interpolation of an elastic partition. The partition serves to prevent gas flow from one side to the other side, i.e., from the intake side and exhaust side or vice-versa.

The partition can preferably be formed as an elastic membrane from a heat-resistant material that is not damaged by the exhaust temperatures.

The invention and additional embodiments and improvements of the invention as well as additional advantages will be explained and described in greater detail based on the drawings.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein the FIGURE shows a schematic front view of an internal combustion engine.

DETAILED DESCRIPTION

The internal combustion engine 10 has four cylinders 11, 12, 13, 14, to which intake manifold pipes 15, 16, 17, 18 lead, which branch off from an intake pipe 19 to the individual cylinders 11, . . . 14. On the exhaust side, each cylinder 11, . . . 14 is followed by exhaust manifold pipes 20, 21, 22, 23, which open into an exhaust gas collection line 24, which leads to a muffler or simply to a tailpipe.

Both in the intake line 19 and in the exhaust line 24, during operation, intake and tailpipe noises are present, which are pulsating and because of their loudness are perceived as highly annoying. The tailpipe noises are necessarily considerably louder than those in the intake area because of the internal combustion processes in the combustion chamber.

For modulating the intake and exhaust gas noises, the intake and exhaust gas pipes 19, 24 lying on the opposite sides of the internal combustion engine 10 on the carburetor or muffler side, based on the connecting line of the cylinders, each have assigned a connecting line 27 and 28, also called extension pipes 27 and 28, the free ends of which are directed toward one another and are connected together gas-tight with interpolation of an elastic partitioning wall or membrane 29.

Because of its elasticity, the membrane 29 transfers sound from the intake side to the exhaust side and vice-versa, wherein gas flow from one side to the other side, i.e., from the intake side to the exhaust side and vice-versa, is prevented.

With this transfer of sound especially from the intake side to the exhaust side, the pulsating noises present in the area of the exhaust line 24 can be influenced additionally, in that by means of suitable acoustic filters, the harmonic spectrum is modified as the vehicle user wishes.

The invention has been described on the basis of a four-cylinder engine. In the same way, influencing of one side by the other side respectively can be accomplished even in the case of engines that have more or less than four cylinders. The connection between exhaust and intake sides can also take place in a great variety of ways and at different positions of intake 25 and exhaust 26 systems, wherein the energy is greater, the closer to the engine 10; gas-tightness and the presence of an acoustically active partition or membrane between the two sides for preventing gas flow from one side to the other are essential.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims. 

1. An internal combustion engine comprising: an engine block having at least one cylinder; intake manifold pipes being provided on an intake side of the cylinder, the intake manifold pipes branching off from an intake line, and over the intake line a fuel-air mixture is supplied; exhaust manifold pipes being provided on an exhaust side of the cylinder, the exhaust manifold pipes opening into an exhaust gas collection line, and over the exhaust line combustion gases are removed towards a muffler and/or tailpipe; and wherein the intake line and the exhaust line are connected together together in an acoustically permeable and gas-tight manner
 2. The internal combustion engine according to claim 1, wherein the intake line and the exhaust lines are connected together gas-tight by an elastic partition or membrane.
 3. The internal combustion engine according to claim 1, wherein, to the intake and exhaust lines on a side of the engine block, extension pipes are respectively connected, free ends of which are connected together by a partition or membrane.
 4. The internal combustion engine according to claim 3, wherein the extension pipes are welded together with the partition or membrane.
 5. An exhaust system comprising: an intake leg configured to provide at least one cylinder of an internal combustion engine with a fuel-air mixture; an exhaust leg configured to direct exhaust gases from the at least one cylinder towards an exit area of the exhaust system; and a connecting member provided between a connection of the intake leg and the exhaust leg for facilitating sound waves from the intake leg to pass through towards the exhaust leg, and for preventing the exhaust gases from the exhaust leg to pass through towards the intake leg.
 6. The exhaust system according to claim 5, wherein the connecting member is an elastic membrane.
 7. The exhaust system according to claim 6, wherein an amount of sound waves that pass from the intake leg to the exhaust leg is based on an elasticity of the elastic membrane.
 8. The exhaust system according to claim 5, wherein the sound waves from the intake leg alter perceived acoustics of the exhaust system.
 9. The exhaust system according to claim 5, wherein the connecting member is only permeable to sound waves. 